Volumes have been said on this topic, and the disquiet and squabbling about where the "hot" slots are installed in a casino are still intense – sixty years after one armed bandits were 1st placed in gambling houses.
The quintessential rule is that the better one armed bandits were installed just inside the entry of the casino; so that potential players passing by would be able to see real jackpot winners and be convinced to come inside and play. Our inference is that this is definitely no longer true.
Nearly all of the major casinos these days are magnificent complexes and now you can’t see inside from the sidewalk, so there is no longer a reason to have the ‘loose’ slots in close proximity to any exits.
Yet another traditional rule is that loose one armed bandits are installed on the major aisles inside the casinos, again so that more persons could see winning jackpots and be roused to play. Importantly however, we find that this also is not a universal rule any more.
What casinos found over the years is that people walking down the busy aisles were frequently on the way to somewhere else. If they played slot games at all, they would simply put in their loose change because they happened to be walking by. Win or lose, they would very often not stop to keep playing. And the very last thing a casino wants is for someone to win a jackpot by playing only a few coins and then not stay to put it all back in!
Today, casinos are constantly changing their philosophy about where to place the loose slot machine games.